feat: amazon OAuth (conditional)

app/config/providers.php

@@ -61,4 +61,9 @@ return [
         'icon' => 'icon-apple',
         'enabled' => false,
     ],
+    'amazon' => [
+        'developers' => 'https://www.dropbox.com/developers/documentation',
+        'icon' => 'icon-amazon',
+        'enabled' => true,
+    ],
 ];

app/controllers/auth.php

@@ -730,6 +730,9 @@ $utopia->get('/v1/auth/oauth/:provider/redirect')
             $defaultState = ['success' => $project->getAttribute('url', ''), 'failure' => ''];
             $validateURL = new URL();
 
+            // Uncomment this while testing amazon oAuth
+            $state = html_entity_decode($state);
+
             if (!empty($state)) {
                 try {
                     $state = array_merge($defaultState, json_decode($state, true));

src/Auth/OAuth/Amazon.php

@@ -0,0 +1,127 @@
+<?php
+
+namespace Auth\OAuth;
+
+use Auth\OAuth;
+
+// Reference Material
+// https://developer.amazon.com/docs/login-with-amazon/authorization-code-grant.html
+// https://developer.amazon.com/docs/login-with-amazon/register-web.html
+class Amazon extends OAuth
+{
+    /**
+     * @var array
+     */
+    protected $user = [];
+
+    /**
+     * @return string
+     */
+    public function getName(): string
+    {
+        return 'amazon';
+    }
+
+    /**
+     * @return string
+     */
+    public function getLoginURL(): string
+    {
+        return 'https://www.amazon.com/ap/oa?' .
+            'client_id='.urlencode($this->appID).
+            '&redirect_uri='.urlencode($this->callback).
+            '&response_type=code'.
+            '&state='.urlencode(json_encode($this->state)).
+            '&scope=profile';
+    }
+
+    /**
+     * @param string $code
+     *
+     * @return string
+     */
+    public function getAccessToken(string $code): string
+    {
+
+        $headers[] = 'Content-Type: application/x-www-form-urlencoded;charset=UTF-8';
+        $accessToken = $this->request(
+            'POST',
+            'https://api.amazon.com/auth/o2/token',
+            $headers,
+            'code=' . urlencode($code) .
+            '&client_id=' . urlencode($this->appID) .
+            '&client_secret=' . urlencode($this->appSecret).
+            '&redirect_uri='.urlencode($this->callback).
+            '&grant_type=authorization_code'
+        );
+        $accessToken = json_decode($accessToken, true);
+
+        if (isset($accessToken['access_token'])) {
+            return $accessToken['access_token'];
+        }
+
+        return '';
+    }
+
+    /**
+     * @param string $accessToken
+     *
+     * @return string
+     */
+    public function getUserID(string $accessToken): string
+    {
+        $user = $this->getUser($accessToken);
+
+        if (isset($user['user_id'])) {
+            return $user['user_id'];
+        }
+
+        return '';
+    }
+
+    /**
+     * @param string $accessToken
+     *
+     * @return string
+     */
+    public function getUserEmail(string $accessToken): string
+    {
+        $user = $this->getUser($accessToken);
+
+        if (isset($user['email'])) {
+            return $user['email'];
+        }
+
+        return '';
+    }
+
+    /**
+     * @param string $accessToken
+     *
+     * @return string
+     */
+    public function getUserName(string $accessToken): string
+    {
+        $user = $this->getUser($accessToken);
+
+        if (isset($user['name'])) {
+            return $user['name'];
+        }
+
+        return '';
+    }
+
+    /**
+     * @param string $accessToken
+     *
+     * @return array
+     */
+    protected function getUser(string $accessToken): array
+    {
+        if (empty($this->user)) {
+            $user = $this->request('GET', 'https://api.amazon.com/user/profile?access_token='.urlencode($accessToken));
+            $this->user = json_decode($user, true);
+        }
+        return $this->user;
+    }
+}